Wissenswertes

The title is a reference to Sergio Martino's earlier giallo Der Killer von Wien (1971) ("The Strange Vice of Mrs. Wardh"), in which the same phrase appears in a mysterious note apparently sent by a killer.

Even though Edwige Fenech gets top billing, she doesn't appear until 32 minutes into the film.

Italian censorship visa # 60781 delivered on 1 August 1972.